Wire stripping tool



Dec. 17, 1963 B. J.,CLENDEN|N 3,114,277

WIRE STRIPPING TOOL Filed April 5. 1961 [7 44 I 5 i 44 24 I 58 I *1 L I:3 5 1 I 2s Barf J. C/ena'en/n INVENTOR.

BY WM mm United States Patent 3,114,277 wmn STRIPPLNG T001, Ber-t1.Clendenin, 4M N. Washington, Marion, Ill. Filed Apr. 5, 1961, Ser. No.100,945 7 Claims. (Cl. 31-95) The present invention generally relates toa hand tool and more particularly a device for stripping the insulationcover from an insulated wire such as those normally employed fortransmitting electrical energy in a building such as a house or thelike.

As is well known, electricians normally require a number of tools forassisting in the various operations normally conducted when practicingtheir trade. One of the tools normally required by an electrician is ascrewdriver. Also, the electrician normally employs some type of toolfor aiding in the removal of insulation from an end portion of aninsulated wire for enabling the wire to be connected to a terminal postor the like. Heretofore, rather elaborate tools have been provided forstripping the insulation from the wire. However, these tools arerelatively expensive and have only the single purpose of removinginsulation. Thus, such tools occupy a considerable space area within thetool box or wherever it is carried. Therefore, it is the primary objectof the present invention to provide a wire stripping assemblyincorporated into the handle of a screwdriver whereby the screwdriverwill be effective for its normal uses and operations and whereby thewire stripping device adds very little to the weight and bulkiness ofthe screwdriver.

Another very important object of the present invention is to provide awire stripping device having a stationary and movable V-shaped bladetogether with a thumb pressure actuated member connected with themovable blade whereby accurate pressure may be exerted on the movableblade and the thumb is also employed for determining when the movableblade contacts the metallic wire thus assuring that the wire will not bepartially cut through by the blade.

Still another object of the present invention is to provide a wirestripping device disposed longitudinally within a screwdriver handle andhaving outwardly flared openings communicated therewith for guiding thewire into the wire stripping device together with an actuator extendinglongitudinally from the end of the screwdriver handle remote from thescrewdriver shank and blade in which the actuator is spring biasedlongitudinally outwardly of the handle and provided with a roundeddome-shaped thumb receiving member for facilitating operation of theblade without interfering with the normal operation of the screwdriver.

Still another important feature of the present invention is to provide awire stripping device incorporated into the handle of the screwdriverwhich is simple in construction, easy to use, effective for itsparticular purposes and relatively inexpensive to manufacture.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a path hereof, whereinlike numerals refer to like parts throughout, and in which:

FIGURE 1 is a perspective view of a screwdriver with the wire strippingdevice of the present invention incorporated therein;

FIGURE 2 is a longitudinal, vertical sectional view taken substantiallyupon a plane passing along section line 2-2 of FIGURE 1 illustrating thestructural details of the invention;

FIGURE 3 is a longitudinal, vertical sectional view taken substantiallyupon a plane passing along section line 3-3 of FIGURE 2 illustratingfurther structural details of the invention;

FEGURE 4 is a transverse sectional view taken substantially upon a planepassing along section line 44 of FIGURE 2 illustrating the relationshipof the blades in their overlapped condition; and

FIGURE 5 is a perspective view of the blade holder and guide element.

Referring now specifically to the drawings, the numeral it? generallydesignates a screwdriver having an elongated shank 12 with aconventional screwdriver blade 14 on one end thereof. The other end ofthe shank 12 is rigidly connected to a screwdriver handle 16 ofgenerally cylindrical cross-sectional area and having longitudinal ribsit; thereon. The particular shape, configuration and size of thescrewdriver lo may vary depending upon the par ticular size requirementof the individual using the device. Reference numeral Zll generallydesignates the wire stripping device which forms the essence of thepresent invention and it is incorporated into the handle 16 of thescrewdriver 10. The handle 16 may be constructed of any suitablematerial normally employed for screwdriver handles such as plastic,wood, metal or the like. The handle 1.6 is provided with alongitudinally extend ing bore 22. therein which communicates with :alaterally extending bore 24. The laterally extending bore 24 extendsdiametrically of the screwdriver handle 16 and has outwardly flared endportions 26 which form a guide for guiding an insulated electric wire 28into the transverse bore 24 so that it may be engaged by the wirestripping device.

The wire stripping device includes a generally longitudinally elongatedholder and guide 30 which includes an upper side wall 32 and a lowerside wall 34 in which the lower side wall is offset from the upper sidewall by an ofiset inclined portion 36. Both the upper side wall and thelower side wall is provided with a continuous side edge or flange 38perpendicular to the upper and lower wall 32 and 34. The edges of theside edges or flanges 38 are inturned as indicated by numeral 40 thusforming a pair of inwardly facing channels 42 for slidably receiving amovable knife 44 and guiding the knife 44 in its vertical reciprocation.Mounted stationarily in the lower portion of the guide and holder 39 isa stationary knife 46 having an outward and upturned lower end portion48 engaging with the bottom edge of the lower wall 34 for rigidlysecuring the stationary knife 46 to the holder 30. The holder 3% isprovided with an opening Stl therein in alignment with the transverseopening 24.

The top edge of the bottom knife 46 is V-shaped as indicated byreference numeral 52 and is also beveled as at 54. The bottom apex ofthe V-shaped top edge 52 is generally in alignment with the bottom ofthe opening as illustrated in FIGURE 3 and the bevel extends upwardlyfrom the bot-tom edge of the opening 50 and the top corner portion ofthe stationary lower knife 46 are engaged with the offset 36 so that theinner surface of the upper wall 32 generally is in alignment with thesurface of the stationary knife 46 remote from the lower wall 34.

The movable blade or knife 44 is also provided with a V-shaped lower end56 which is inverted in relation to the Vshaped edge 52 of the lowerblade or knife 46 and is also beveled or inclined as indicated bynumeral 58. The bevel of the knife or blade 44 is such that it isgenerally parallel with the bevel on the knife or blade 46 for providingcooperating sharpened edges slidably disposed immediately adjacent eachother. As illustrated in FIGURE 2, the blades 44 and 46 are alwaysslightly overlapped and the bottom end of the blade 44 will serve toretain the blade 46 in the offset portion of the holder inasmuch as theblade 44 is accurately guided in its vertical movement by the inwardlyfacing channels 42.

The upper end of the holder 30 is engaged by a transverse washer member60 for anchoring the holder in place and the washer 60 is provided witha central opening 62 receiving an operating plunger 64 that is attachedto the upper end of the knife or blade 44 by virtue of a rivet 66 orother suitable fastening means. For purposes of alignment, the lower endof the plunger 64 is recessed in order to receive the blade 44- so thatthe longitudinal axis of the plunger 64 is generally in alignment withthe longitudinal axis of the blade or knife 44.

Forming a closure for the upper end of the bore 22 is a screwthreadedplug 68 having a peripheral flange 7G engaging the outer end of thescrewdriver handle 16. The plug 68 is provided with a longitudinal bore'72 slidably receiving the plunger 64. The plunger 64 is provided with atransverse and laterally extending pin 74 which forms a limit foroutward movement of the plunger 64 inasmuch as it will engage with theplug 68 and also the pins '74 forms a seat for the upper end of a coilcompression spring 76 which has the lower end thereof engaging thewasher 60 thereby resiliently urging the plunger 64 outwardly andresiliently urging the knife blade 44 upwardly or away from thestationary blade or knife 46. For depressing the plunger 64, there isprovided a generally dome-shaped thumb engaging actuator or pressurereceiving member 78 that is attached to the upper end of the plunger 64by any suitable means such as a screwthreaded connection 8%. The uppersurface of the pressure receiving member 78 is convexly curved as at 82and has a diameter generally equivalent to the diameter of thescrewdriver handle 16 so that if it is required to exert longitudinalpressure on the screwdriver during normal operation thereof, thepressure member 78 may be forced inwardly against the plug 68 whereuponpressure may then be exerted on the end of the screwdriver handle in theusual manner.

The size of the transverse bore 24 will generally preclude any possibledanger of insertion of fingers or the like into the area between theknife blade. However, the outward taper 26 will guide the insulated wire28 into the diamond-shaped area formed by the partially overlappedblades as illustrated in FlGURE 2. Then upon depression of the plunger64 by exerting some pressure thereon, the insulation will be cut throughto the wire at four spaced points and the remainder of the insulationwill be substantially severed thereby enabling the insulation to bestripped from the wire by exerting longitudinal force on the insulationwhich is very easy to accomplish since it is only necessary to move thescrewdriver handle longitudinally of the insulated wire after theinsulation has been partially severed or substantially completelysevered. This eliminates the necessity for rotation of the wirestripping device about the longitudinal axis of the insulated wirealthough this could be done if required in certain instances.

Inasmuch as the bore 22 need not be the same size throughout its length,the lower portion thereof is only of sufficient size to receive theholder and guide 30 and it also is within the purview of the presentinvention to have the holder molded into the handle if made of plasticalthough the device is also adaptable for use with various types ofscrewdriver handles. The holder 3% also is provided with a notch 84extending downwardly in the upper wall 32 from the upper edge thereof.This notch serves to enable movement of the lower recessed end of theplunger 64 during normal operation thereof thus further enabling thelongitudinal axis of the plunger to be aligned with the longitudinalaxis of the movable blade 44 thereby eifectively transmittinglongitudinal force to the blade 44.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention asclaimed.

What is claimed as new is as follows:

1. A wire stripping tool comprising an elongated body member having alongitudinal bore and a transverse bore therein, said transverse borecommunicating with the longitudinal bore adjacent the inner end thereof,said longitudinal bore communicating with one end of said body member, astationary blade disposed in the inner end of said longitudinal bore, amovable blade longitudinally movably mounted within said longitudinalbore, said movable blade being continuously in overlapping relation tothe stationary blade, actuating means connected to said movable bladeand extending axially from the longitudinal bore, spring means engagedwith said actuating means for urging the movable blade to a retractedposition, said blades each having V-shaped sharpened edges defining anopening therebetween in alignment with the transverse bore when themovable blade is in retracted position, and a holder and guide means forsaid blades, said holder and guide means including a lower side wall, anupper side wall offset from the lower side wall by the width of thestationary blade, longitudinally inwardly facing edge channels, and atransverse opening therethrough, said opening being in alignment withthe transverse bore in the elongated body and the sharpened edges of thetwo blades, means rigidly securing the stationary blade to the lowerside wall with the outer surface of the stationary blade in alignmentwith the offset upper wall, and the movable blade being positionedwithin and between the inwardly facing edge channels and against theupper side wall.

2. The structure as defined in claim 1 wherein the means securing thestationary blade comprise an upturned lower end portion on thestationary blade engaged over the lower end of the holder and guidemeans.

3. A wire stripping tool comprising an elongated body member having alongitudinal bore and a transverse bore therein, said transverse borecommunicating with the longitudinal bore adjacent the inner end thereof,said longitudinal bore communicating with one end of said body member, astationary blade disposed in the inner end of said longitudinal bore, amovable blade longitudinally movably mounted within said longitudinalbore, said movable blade being continuously in overlapping relation tothe stationary blade, actuating means connected to said movable bladeand extending axially from the longitudinal bore, spring means engagedwith said actuating means for urging the movable blade to a retractedposition, said blades each having V-shaped sharpened edges defining anopening therebetween in alignment with the transverse bore when themovable blade is in retracted position, closure means removably sealingthe longitudinal bore at said one end, said closure means provided withan opening therethrough so as to accommodate the actuating means, saidactuating means comprises a plunger secured to the movable blade, saidplunger extending through the opening in the closure means, a domeshapedengaging member attached to the upper end of the plunger, said engagingmember having a diameter approximately equivalent to the diameter of theelongated body, and a laterally extending pin through the plungeradjacent the inner side of the closure means so as to limit the outwardmovement of the plunger.

4. The structure as defined in claim 3 together with a holder and guidemeans positioning the stationary blade in the bottom of the longitudinalbore and slidably securing the movable blade thereto.

5. The structure as defined in claim 3 wherein the spring means isengaged between the laterally extending pin and the top of the holderand guide means.

6. A wire stripping tool comprising an elongated body member having alongitudinal bore and a transverse bore therein, said transverse borecommunicating with the longitudinal bore, a stationary blade disposed insaid longitudinal bore, a movable blade longitudinally movably mountedwithin said longitudinal bore, said movable blade being in continuouslyoverlapping relation to the stationary blade, actuating means connectedto said movable blade and extending from the longitudinal bore, springmeans engaged with said actuating means for urging the movable blade toa retracted position, said blades each having sharpened edges definingan opening therebetween in alignment with the transverse bore when themovable blade is in retracted position, and a holder and guide means forsaid blade, said holder and guide means including a lower side wall, anupper side wall offset from the lower side wall by the width of thestationary blade, longitudinally inwardly facing edge channels, and atransverse opening therethrough, said opening being in alignment withthe transverse bore in the elongated body and the sharpened edges of thetwo blades, means rigidly securing the stationary blade to the lowerside wall with the outer surface of the stationary blade in alignmentwith the offset upper wall, and the movable blade being positionedwithin and between the inwardly facing edge channels and against theupper side wall.

7. A wire stripping tool comprising an elongated body member having alongitudinal bore and a transverse bore therein, said transverse borecommunicating with the longitudinal bore, said longitudinal borecommunicating with one end of said body member, a stationary bladedisposed in said longitudinal bore, a movable blade longitudinallymovably mounted within said longitudinal bore, said movable blade beingcontinuously in overlapping relation to the stationary blade, actuatingmeans connected to said movable blade and extending axially from thelongitudinal bore spring means engaged with said actuating means forurging the movable blade to a retracted position, said blades eachhaving sharpened edges defining an opening therebetween in alignmentwith the transverse bore when the movable blade is in retractedposition, closure means removably sealing the longitudinal bore at saidone end, said closure means provided with an opening therethrough so asto accommodate the actuating means, said actuating means com prising aplunger secured to the movable blade, said plunger extending through theopening in the closure means, and a laterally extending pin through theplunger adjacent the inner side of the closure means so as to limit theoutward movement of the plunger.

References Cited in the file of this patent UNITED STATES PATENTS2,819,520 Eyles Jan. 14, 1958 2,834,241 Chowning May 13, 1958 2,848,914Gottfried Aug. 26, 1958 2,989,881 Lavietes June 27, 1961 2,995,052Funcik Aug. 8, 1961 FOREIGN PATENTS 119,711 Austria Nov. 10, 1930611,822 Great Britain Nov. 14, 1948 780 Great Britain Oct. 22, 1914

1. A WIRE STRIPPING TOOL COMPRISING AN ELONGATED BODY MEMBER HAVING ALONGITUDINAL BORE AND A TRANSVERSE BORE THEREIN, SAID TRANSVERSE BORECOMMUNICATING WITH THE LONGITUDINAL BORE ADJACENT THE INNER END THEREOF,SAID LONGITUDINAL BORE COMMUNICATING WITH ONE END OF SAID BODY MEMBER, ASTATIONARY BLADE DISPOSED IN THE INNER END OF SAID LONGITUDINAL BORE, AMOVABLE BLADE LONGITUDINALLY MOVABLY MOUNTED WITHIN SAID LONGITUDINALBORE, SAID MOVABLE BLADE BEING CONTINUOUSLY IN OVERLAPPING RELATION TOTHE STATIONARY BLADE, ACTUATING MEANS CONNECTED TO SAID MOVABLE BLADEAND EXTENDING AXIALLY FROM THE LONGITUDINAL BORE, SPRING MEANS ENGAGEDWITH SAID ACTUATING MEANS FOR URGING THE MOVABLE BLADE TO A RETRACTEDPOSITION, SAID BLADES EACH HAVING V-SHAPED SHARPENED EDGES DEFINING ANOPENING THEREBETWEEN IN ALIGNMENT WITH THE